June, I9I5-] OsBURN : STUDIES IN SyRPHID.E. 139 



STUDIES IN SYRPHID^— IV. SPECIES OF 



ERISTALIS NEW TO AMERICA, WITH 



NOTES ON OTHERS. 



By Raymond C. Osburn, 



New York City. 



It is well known that numerous species of insects first described 

 from Europe have since been found to occur in North America. 

 This is perhaps true to a larger extent in the Syrphid^ than in any 

 other dipterous family, as not only are the syrphids very active on 

 the wing, but they are also more independent in their food habits 

 than are most insects. Many of them are predaceous in the larval 

 stage, feeding on soft-bodied insect larvae and aphids, while others 

 pass the larval stage in decayed wood or in water containing decaying 

 matter. The general distribution of these makes it possible for 

 many of the syrphids to find suitable conditions for life over wide 

 areas. Thus Eristalis tcnax (L.) has attained to a world-wide dis- 

 tribution, as sewage and other filth in which it may breed occur 

 everywhere. A few other species are also widely distributed in both 

 hemispheres and many more are circumpolar. 



Even species which are more limited in the matter of food may 

 sometimes be transported, as is the case with Merodon equestris 

 (Fab.), parasitic in bulbs of liliaceous plants. This European species 

 has been repeatedly taken on both the Atlantic and Pacific coasts 

 and is possibly established in some localities. 



In the present paper the writer wishes to report the occurrence 

 of two more well-known European species in America and to estab- 

 lish a third hitherto reported doubtfully. 



Eristalis arbustorum (Linne). 



The attention of the writer was first attracted to the presence of 

 this species in America in the summer of 1910 when, on July lo a 

 number of specimens were taken at Ft. Lee, N. J. The flies were 

 common about the flowers of the wild carrot, but only a few were 

 taken as they were supposed to be only the common E. meigcnii 

 Wiedemann. On pinning them, however, it was noticed that the 



